diff --git a/libboost.spec b/libboost.spec
index 174c034..18d8ce4 100644
--- a/libboost.spec
+++ b/libboost.spec
@@ -2,7 +2,7 @@
 %define pckmajver %(echo %version | cut -d. -f1-2 | tr . _)
 Name:          libboost
 Version:       1.85.0
-Release:       3mamba
+Release:       4mamba
 Summary:       Free peer-reviewed portable C++ source libraries
 Group:         System/Libraries
 Vendor:        openmamba
@@ -30,7 +30,8 @@ BuildRequires: libicu-devel >= 67.1
 BuildRequires: libpython3-devel >= 3.11
 BuildRequires: python-numpy-py3
 BuildRequires: openmpi-devel
-BuildRequires: boost-jam
+Provides:      boost-jam
+Obsoletes:     boost-jam <= 3.1.18-1mamba
 
 %description
 The Boost libraries provide free peer-reviewed portable C++ source libraries.
@@ -158,7 +159,6 @@ done
 %{_includedir}/boost/*
 %{_libdir}/libboost_*.so
 %{_libdir}/libboost_*.a
-#%exclude %{_libdir}/mpi.so
 %dir %{_libdir}/cmake/Boost-%{version}
 %{_libdir}/cmake/Boost-%{version}/Boost*.cmake
 %{_libdir}/cmake/Boost*.cmake
@@ -172,6 +172,9 @@ done
 %{_libdir}/libboost_numpy311.so.*
 
 %changelog
+* Mon May 06 2024 Silvan Calarco <silvan.calarco@mambasoft.it> 1.85.0-4mamba
+- remove and provide/obsolete boost-jam requirement
+
 * Mon Apr 22 2024 Automatic Build System <autodist@openmamba.org> 1.85.0-3mamba
 - aarch64: rebuilt with libbacktrace